The purpose of this project is to study the biochemical basis for the various monoamine oxidases (E.C. 1.4.3.4.). Our present interests are: (1) To identify the changes that occur in monoamine oxidase activity with age; (2) to determine the characteristics of cardiovascular amine oxidase and compare them with the enzymes in neuronal tissues and (3) to continue our survey of the types and activities of monoamine oxidase in autopsy material from individuals with various psychiatric disorders. BIBLIOGRAPHIC REFERENCES: Neff, N.H., Garrison, C.K., Seaborg, J.B., Fuentes, J. and Wyatt, R.J.: Trace amines and the monoamine oxidases. In Usdin, E. and Sandler, M. (Eds.). : Trace Amines and the Brain. New York, Marcel Dekkar, Inc., 1976, pp. 41-57. Trepel, J.B., Wyatt, R.J. and Neff, N.H.: Differential distribution of type A and B monoamine oxidase in neuronal tissues. Eur. J. Pharmacol. 43: 373-375, 1977.